In recent years it has become possible to discard the relatively massive vacuum type housings and encapsulations used for protectively enclosing semiconductor devices. This has occurred because of the development of surface passivation films comprised generally of inorganic components, typically oxides and nitrides of silicon as well as certain other elements. There are also useful for this purpose a variety of coatings which may be characterized as glasses and which contain particular elements tailored to passivate the surface conditions of semiconductor devices.
However, despite the electronic passivation of semiconductor devices by such means it has remained desirable to provide some protection for the active portion of the device, at least from gross contamination, and for mechanical purposes, particularly during assembly of the device into various apparatus. More particularly, the organic coating provides final humidity protection on the active surface of the device. For this purpose, certain organic polymers, in particular, silicone resins, are used. Various arrangements have been devised for applying such resin films, almost exclusively after formation of the individual device and after mounting in apparatus assemblies. Applying such protective film at this point is undesirable inasmuch as the beam lead device is usually bonded with the active surface toward the mounting substrate. Applying resin to the active surface of the device is costly and unlikely to cover completely without undue spreading.